Movies for Partial Differential Equations


Transport equation:   ut + ux = 0

            

 

 

Transport with decay:   ut + ux + u = 0

            

 

 

Nonuniform Transport:   ut + ux / (x2 + 1) = 0

            

 

 

Nonuniform Transport:   ut + (x2 - 1) ux = 0

            

 

 


Nonlinear Transport:   ut + u ux = 0,   straight line solutions

            

 

 

Nonlinear Transport:   ut + u ux = 0,   rarefaction wave

            

 

 

Nonlinear Transport:   ut + u ux = 0,   shock wave

            
Shock wave solution
Multi-valued solution corresponding to the shock wave
Equal area rule for shock wave

 

 

Nonlinear Transport:   ut + u ux = 0,   initial step function

            
Rarefaction wave
Shock wave
Multi-valued solution corresponding to the shock wave
Equal area rule for shock wave

 

 


Heat equation:   ut = uxx,   Dirichlet boundary conditions

            

 

 


Heat equation:   ut = uxx,   periodic boundary conditions

            

 

 

Heat equation:   ut = uxx,   denoising

            

 

 


Wave equation:   utt = uxx,   particles and waves

The wave solution u(t,x) = cos t sin x = (sin(x-t) + sin(x+t))/2
Constitutent traveling waves (particles)
Particles and Waves

 

 

Wave equation:   utt = uxx,   interaction of waves

            

 

 

Wave equation:   utt = uxx,   Dirichlet boundary conditions

            

 

 

Wave equation:   utt = uxx,   odd periodic extension

            

 

 

Wave equation:   utt = uxx,   hammer blow

            
Dirichlet boundary conditions
Neumann boundary conditions